From earliest times, the clever people ('Greeks') and the devout people ('Jews') have rejected Biblical Christianity. It flies in the face of modern intellectualism, and defies the pride of the good-works righteousness than many deeply religious people hold.
That I can be saved from my sin by a crucified God is a ludicrous proposition to so many. But to us, it is the power of God.
18 For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God. 19 For it is written:
“I will destroy the wisdom of the wise,
And bring to nothing the understanding of the prudent.”
20 Where is the wise? Where is the scribe? Where is the disputer of this age? Has not God made foolish the wisdom of this world? 21 For since, in the wisdom of God, the world through wisdom did not know God, it pleased God through the foolishness of the message preached to save those who believe. 22 For Jews request a sign, and Greeks seek after wisdom; 23 but we preach Christ crucified, to the Jews a stumbling block and to the Greeksfoolishness, 24 but to those who are called, both Jews and Greeks, Christ the power of God and the wisdom of God. 25 Because the foolishness of God is wiser than men, and the weakness of God is stronger than men.
1 Corinthians Chapter 1.